1. Field of the Invention
The presently disclosed subject matter relates to an image recording apparatus which can suppress occurrence of an image defect caused by a defective recording element, and a control method thereof.
2. Description of the Related Art
There has been known an ink-jet recording apparatus (an image recording apparatus) which forms an image on a recording medium by ejecting ink from a plurality of ink-ejecting nozzles (simply referred to as a nozzle below) provided on a recording head. In the ink-jet recording apparatus, there is generated a non-ejection nozzle which cannot eject ink due to clogging or breakdown over time. When the non-ejection nozzle as described above is generated, stripe unevenness (a white stripe or the like) caused by the non-ejection nozzle occurs in a single-pass-type ink-jet recording apparatus when a recorded image is observed. The stripe unevenness is caused not only by the non-ejection nozzle described above, but also by an “ejection largely-deflected nozzle” having a large amount of ink flight deflection. Therefore, a technique for detecting the generation of a defective nozzle such as the non-ejection nozzle and the ejection largely-deflected nozzle, and a technique for suppressing the occurrence of stripe unevenness caused by the defective nozzle have been developed.
For example, an image recording apparatus according to Japanese Patent No. 4915252 detects a defective nozzle by recording a test chart on a recording medium by an ink-jet head, and analyzing a reading result obtained by reading the test chart by an optical reading device such as an in-line sensor.
An image recording apparatus according to Japanese Patent Application Laid-Open No. 2012-071474 detects a defective nozzle in basically the same method as that of Japanese Patent No. 4915252, and thereafter suppresses the occurrence of stripe unevenness by performing so-called non-ejection correction in which ink ejection from the defective nozzle is prohibited, and the output densities of normal adjacent nozzles adjacent to the defective nozzle are increased. The image recording apparatus according to Japanese Patent Application Laid-Open No. 2012-071474 also determines a correction parameter for non-ejection correction that varies with a difference in a landing interference pattern based on an arrangement form of nozzles on an ink-jet head, and correspondence information indicating a correspondence relation between a plurality of types of landing interference patterns and respective nozzles. In the image recording apparatus, input image data is modified so as to compensate for the output of the defective nozzle by use of nozzles other than the defective nozzle by referring to the correction parameter for non-ejection correction based on the positional information of the defective nozzle and performing a corrective calculation of the input image data using the correction parameter.